I have fairly limited experience but in the experience I do have, 5 months is too old for a high heat method of cooking. I have eaten 5 month olds roasted SUPER low in a tight fitting roaster pan (whole and parted- taking several hours). While I liked the bird that way, none of my friends did because the meat is much firmer than you buy at the store. (Think sturdy knife to cut the leg meat off).
I would suggest crock potting it or something similar, but remember- do not let the water/fluid get above 180 degrees or so. I read that once the water/fluid gets above 180 degrees, the heat contracts the muscle tissue and breaks the muscle cell walls, which does two things: (1) toughens/tightens the meat and (2) expels all the moisture out of the muscle tissue... so your bird will be tough and dry no matter how long it is cooked in fluids if cooked at too high of a temperature. (This is why pot roast can sometimes seem/feel very dry even though it has cooked all day in fluids - bc the temp got too high at some point. Once the heat gets too high the tissue tightening and fluid expulsion can never be reversed). It is also good to note that the reason 'tough' meats tenderize from very long and low cooking is that there is enough connective tissue etc in the muscles that the long cooking time gelatinizes the connective tissue. The gelatinization 'adds' moisture to the muscle tissue. So cuts without much connective tissue or intramuscular fat wont really get more tender from longer cooking.
This is just my experience, hope it helps.